Paperboard sleeve for trays

ABSTRACT

A substantially open-ended paperboard sleeve for a tapered tray containing a ready-to-cook comestible, having a new end construction designed to hold the tray in place in the sleeve. The end construction includes a restraining panel, biased against an end panel of the tray, hingedly attached to the bottom panel of the sleeve and extending inwardly of the sleeve. The end construction also includes two locking panels hingedly connected to the side panels of the sleeve and extending inwardly of the sleeve. The restraining panel is provided with a pair of fingers, extending inwardly of the sleeve and in cradling relationship to the end panel of the tray. Each locking panel overlies a respective finger thereby preventing the restraining panel from moving outwardly of the sleeve and away from the tray.

United States Patent [72] inventors Thomas Dominic Pawlowski Neenah;Richard Gene Mathison, Larsen, both of Wis. [2|] Appl. No 877,390 [22]Filed Nov. 17, 1969 [45] Patented Nov. 9, 197! [73] Assignee AmericanCan Company New York, N.Y.

[541 PAPER BOARD SLEEVE FOR TRAYS 5 Claims, 22 Drawing Figs.

[521 0.8. Ci 229/39 R, 206/4514. 229/51 TS. 229/40 [5 l] Int. Cl 865d5/10 [50] Field of Search 229/37 R. 39 R. 39 B. 34 R, 34 B; 206/45. 14,45.31

[56] References Cited UNITED STATES PATENTS 2.274.253 2/1942 Howell206/4531 X 2.960,!49 ll/l960 Throssel $330,465 7/1967 Davidsonetal.

Primary Examiner-Joseph R. Leclair Assistant Examiner-Steven E. LipmanAnorneys- Robert P. Auber George P. Ziehmer and Frank 8.

Charlton 229/34 X 206/45. l4 X ABSTRACT: A substantially open-endedpaperboard sleeve for a tapered tray containing a ready-to-cookcomestible. having a new end construction designed to hold the tray inplace in the sleeve. The end construction includes a restraining panelbiased against an end panel of the tray. hingedly attached to the bottompanel of the sleeve and extending inwardly of the sleeve. The endconstruction also includes two locking panels hingedly connected to theside panels of the sleeve and extending inwardly of the sleeve. Therestraining panel is provided with a pair of fingers. extending inwardlyof the sleeve and in cradling relationship to the end panel of the tray.Each locking panel overlies a respective finger thereby preventing therestraining panel from moving outwardly of the sleeve and away from thetray.

PAPER BOARD SLEEVE FOR TRAYS BACKGROUND OF THE INVENTION In recentyears, packages of frozen food capable of being taken from the homefreezer and placed directly into a home oven for heating and servinghave gained wide consumer acceptance. Typically, such frozen,heat-and-serve packages have included an aluminum, generally rectangulartray or dish containing the frozen comestible with a paperboard or foiltop closure. The sidewalls of such trays have typically been taperedoutwardly from the bottom to the top for ease of filling. In addition,the trays have typically been provided with an annular flange about thetop thereof which has been crimped about the paperboard or foil closure,thereon, to create a greater overall tapered effect in the finishedtray.

Unfortunately, the above described tapered gray and closure thereon haveusually been relatively susceptible to damage from the ordinary abuseassociated with transporting these packages from the factory to thegrocers freezer. Furthermore, there has been an additional problemassociated with such trays and closures due to the relatively small areaavailable for printed matter and decoration thereon.

To solve these problems, such trays have been packed in decoratedpaperboard boxes, thereby affording some added protection against abuseto the tray and also allowing for convenient printing and adequatepresentation of printed matter on the tray package. The consumer, ofcourse, removes the tray from the decorated box before heating thecontents thereof.

However, such paperboard packageshave had several serious commercialdrawbacks; viz, the consumer could not see the aluminum tray within theclosed package and was therefore suspicious as to the exact sizethereof; and the tray tended to bounce around in the package, therebycreating further doubts in the consumer's mind as to the size and natureof the contents of thepackage. These drawbacks have tended to discouragethe sale of frozen, heat-and-serve trays in paperboard packages.

SUMMARY OF THE INVENTION In order to overcome the drawbacks in previouspaperboard packages for tapered trays, as indicated in the Background ofthe Invention, this invention relates to a substantially openendedpaperboard sleeve for a tapered tray, having a unique end constructionincluding a restraining panel. The restraining panel is biased againstan end panel of the tray, is hingedly attached to the bottom panel ofthe sleeve and extends inwardly of the sleeve. The restraining panel isprovided with a pair of spaced fingers, extending inwardly of the sleeveand laterally of the end panel of the tray. The end construction furtherincludes two locking panels, each hingedly attached to aside panel ofthe sleeve, extending inwardly of the sleeve, and each overlying arespective finger on the restraining panel.

Numerous other advantages of the invention will be apparent as it isbetter understood from the following description, which, taken inconnection with the accompanying drawings, discloses a preferredembodiment thereof.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view of a paperboard blankto be formed into a paperboard sleeve, not showing the glue patterns tobe used.

FIG. 2 is a perspective view of the formed paperboard sleeve, with atapered tray inserted therein.

FIG. 3 is a fragmentary, perspective view of an end portion of thesleeve shown in FIG. 2 showing the restraining panel folded inwardlyagainst the tray.

FIG. 4 is a perspective view of the closed paperboard sleeve enclosingthe tray.

FIG. 5 is a longitudinal, sectioned view taken along line 5- 5 in FIG. 4of the closed sleeve shown in FIG. 4, the tray being fully shown inelevation.

FIG. 6 is a transverse sectioned view taken along line 6-6 in FIG. 5 ofthe closed sleeve shown in FIG. 4, the tray being fully shown inelevation.

FIG. 7 is a fragmentary plan view of a first modified paperboard blankto be formed into a first modified paperboard sleeve. 7

FIG. 8 is a fragmentary, perspective view of an end portion of the firstmodified sleeve similar to FIG. 2.

FIG. 9 is a fragmentary view of the formed first modified sleeve similarto FIG. 4.

FIG. 10 is a fragmentary, longitudinal sectioned view of the formed,first modified sleeve, similar to FIG. 5, the tray being shown inelevation.

FIG. 11 is a fragmentary plan view of a second modified paperboard blankto be formed into a second modified paperboard sleeve.

FIG. 12 is a fragmentary, perspective view of the end portion of thesecond modified sleeve similar to FIG. 2.

FIG. 13 is a fragmentary, perspective view similar to FIG. 12, showingthe folded restraining panels extending outwardly of the second modifiedpaperboard sleeve.

FIG. 14 is a fragmentary, perspective view similar to FIG. 3, showingthe folded restraining panel extending inwardly of the second modifiedsleeve.

FIG. 15 is a fragmentary, perspective view similar to FIG. 4, showingthe folded restraining panel and the locking panels enclosing the tray.

FIG. 16 is a fragmentary, longitudinal sectioned view taken along line16l6 of FIG. 15, similar to FIG. 5, the tray being shown in elevation.

FIG. 17 is a fragmentary, perspective view similar to FIG. 12 of a thirdmodified paperboard sleeve.

FIG. 18 is a fragmentary, perspective view similar to FIG. 15 of thethird modified sleeve enclosing the tray, a corner of the sleeve beingpartially cut away.

FIG. 19 is a fragmentary plan view similar to FIG. 7 of a fourthmodified paperboard blank to be formed into a fourth modified paperboardsleeve.

FIG. 20 is a fragmentary, perspective view of an end portion of thefourth modified sleeve, similar to FIG. 8.

FIG. 21 is a fragmentary, perspective view of an end portion of thefourth modified sleeve similar to FIG. 9.

FIG. 22 is a fragmentary, longitudinal sectioned view taking along line22-22 in FIG. 21, similar to FIG. 10, the tray being shown in elevation.

DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION As a preferred orexemplary embodiment of the instant invention, FIG. 1 shows a blank,generally 10, to be formed into a sleeve, also generally 10, for atapered tray, generally 30. The blank 10 is made from any relativelyinexpensive, rigid material such as paperboard or plastic that iscapable of affording satisfactory protection and decoration to a taperedtray, to be enclosed in the formed sleeve 10. The rigid materialselected for the blank and sleeve 10 is also adapted to having aplurality of panels hingedly attached thereto.

The blank 10 of the preferred embodiment, shown in FIG. 1, as well asthe sleeve 10, shown in FIG. 2, are substantially symmetrical abouttheir lateral midsections. The blank and sleeve of the preferredembodiment are symmetrically provided with the end construction of theinstant invention at both ends, enabling the consumer to see the endpanels 31 of the tray 30 inside the formed sleeve 10 through either endthereof. However, for the tray to be sufficiently visible to satisfy aconsumer, it is believed that the and construction of the instantinvention need be provided at only one end of the sleeve, it not beingnecessary that the blank and sleeve 10 of the instant invention besymmetrical. Because the provision of symmetrical end constructions inthe blanks and sleeves of the instant invention is considered optional,only half of each modified blank 100, 200 and 40 is shown in FIGS. 7, 11and l9 and correspondingly only one-half of each modified sleeve 100,200, 300 and 404) is shown in FIGS. 8, 12, 17 and 20, and the followingdiscussion of the preferred embodiments will similarly concern onlyone-half of each blank and sleeve, although it is intended to beapplicable to the other half thereof. Thus, the discussion of thepreferred embodiment of the instant invention is being restricted to onehalf thereof except where the other half is particularly relevant,although the end construction of the instant invention, in all the rigidsleeves 10, 100, 200, 300 and 400 of the preferred embodiment, has beenprovided at both sleeve ends to promote the viewing of the taperedtrays.

As shown in FIG. 1, the paperboard blank 10 to be formed into thepaperboard sleeve 10 of the instant invention includes the followinghingedly connected panel members: a first side panel 14, a top panel 13,a second side panel 12, a bottom panel 11, and a glue flap 15. Hingedlyattached to the bottom panel 11 is a restraining panel 16, and hingedlyattached to each side panel 12 and 14 is a locking panel 17. The panelmembers 11-17 are capable of hinged movement relative to each other dueto scored or otherwise formed hinge lines or lines of weakness lyingbetween adjacent panel members, a first hinge line 27 being locatedbetween the restraining panel 16 and the bottom panel 11, and a secondhinge line 29 being located between the side panels 12 and 14 and eachlocking panel 17.

The blank 10 in FIG. 1 is further provided with a zipper pattern 22 inthe second side panel 12, consisting of a plurality of cut lines, andwith a preweakened, removable area 18. The zipper pattern 22 and theremovable area 18 are adapted to permit the completed sleeve 10 to beeasily destroyed by tearing the second side panel 12 apart along thezipper pattern 22, the removable area 18 promoting the grasping andtearing of the second side panel 12.

The blank 10 is still further provided on the exterior surface of theglue flap 15 with an adhesive capable of holding the glue flap 15 to thefirst side panel 14. The adhesive selected may be either pressuresensitive or heat sensitive, the former being preferable if the formedsleeve is to be stored for a length of time and the latter beingpreferable if the unformed blank is to be stored, before forming thesleeve. Of course, for the same purpose, the interior surface of thefirst side panel 14 could also be provided with adhesive along the freeedge thereof.

Shown in FIG. 2 is the paperboard sleeve 10 formed from the justdescribed blank 10, the first side panel 14 being adhesively secured toand overlapping the glue flap 15. Because each panel 11-17 is hingedlyconnected in the blank 10, the sleeve 10 may be formed with relativeease by securing the glue flap 15 to the first side panel 14. As thesleeve 10 is initially formed, the restraining panel 16 and the lockingpanel 17 are shown extending outwardly of the paperboard sleeve 10 atboth ends thereof.

The restraining panel 16 is hingedly secured to the bottom panel 11. Therestraining panel 16 is provided with two outwardly or longitudinallyextending fingers 26, which fingers extend from the lateral portions ofthe restraining panel. The exact placement and configuration of thefingers 26 will be hereinafter more fully described.

After the sleeve 10 is formed, the tapered tray 30 is inserted therein,the smaller, bottom portion of the tray resting on the bottom panel 11and the larger, top portion of the tray being located in near proximityto the top panel 13. Movement of the tray 30 is restrained somewhat byclosing one end of the sleeve 10 in a manner appropriate to theconstruction of the end. The method used to close this first end will,of course, correspond to the method used to form the end construction ofthe instant invention if the sleeve is symmetrical as shown in FIG. 2.The exact method of forming the end construction of the sleeve of theinstant invention will be hereinafter explained with reference to FIGS.3 and 4.

With regard to the structure of the tapered tray 30 to be inserted intothe sleeves 10, 100, 200, 300 and 400 of the instant invention, onlyseveral portions thereof are important to the cradling efiect of the endconstruction of the instant invention. The important portions of thetray 30, which will be hereinafter referred to, are as follows: the trayend panels 31 which are the portions of the tray 30 that can be seenthrough the end construction of the sleeve 10; the tray side panels 33;the rounded tray comers 32 which constitute the areas of the traybetween the tray end panels 31 and the tray side panels 33; and the trayflange 34 which surrounds the top of the tapered tray 30. Of course, itshould be obvious that the end construction of the instant invention isnot limited to tapered trays nor to the rounded tray corners 32 as shownin the figures. However, although the restraining panels 16 and thelocking panels 17 of the instant invention could be easily adapted toaccommodate nonrounded corners and nontapered trays, both rounded traycorners and tapered tray sidewalls have been found preferable inconnection with the preferred embodiments of the paperboard sleeve ofthe instant invention.

As shown in FIG. 3, after the tray 30 is inserted in the sleeve 10, therestraining panel 16 and the fingers 26 thereon are hingedly rotatedabout hinge line 27 inwardly of the sleeve until the restraining panel16 is biased against the tray end panel 31 of the tray 30. Therestraining panel 16 is designed to urge the tray 30 inwardly of thesleeve 10 and to obstruct movement of the tray outwardly of the sleeve10 through the substantially open end thereof. The fingers 26 on therestraining panel 16 are adapted to closely surround the tray corners 32and the lateral portions of the tray side panels 33 to provide acradling effect for the tray end panel 31 when the restraining panel 16is biased there against. The cradling effect is intended to restrainlateral movement of the tray 30 within the sleeve 10, the fingers 26extending laterally of the tray end panel 31, inwardly of the sleeve 10.Because the length of the fingers 26 is relatively limited by the heightof the tray, the principal restraining action of the fingers 26 isdirected to the tray corners 32. To insure, in a relatively low sleeve,the cradling effect of the fingers 26 and the restraining effect of therestraining panel 16 against portions of the tray 30, the fingers 26 andthe restraining panel 16 are relatively closely shaped to the contoursof the tray corners 32 and the tray end panels 31, respectively.Thereby, when the restraining panel 16 is biased against the tray 30,the tray is restrained against both lateral and longitudinal movementsrelative to the sleeve 10 and the end construction of the instantinvention.

The length of each finger 26 is, of course, adapted so that it does notstrike the top panel 12 or the tray flange 34 when the restraining panel16 is rotated inwardly of the sleeve 10. The width of each finger 26 isadapted so that it passes relatively freely between the side panels 12and 14 and the tray side panels 33 when the restraining panel 16 isrotated inwardly of the sleeve 10. The length and width of each finger26 depends then on the dimensions of the tray 30, the sleeve 10 and therelative position of the tray in the sleeve when the restraining panel16 is folded inwardly of the sleeve.

After the restraining panel 16 and the fingers 26 thereon arepositioned, substantially cradling the end panel 31 of the tray 30 asshown in FIG. 3, the pair of locking panels 17 is hingedly rotated aboutthe second hinge line 29 and is urged inwardly of the sleeve 10. Inorder for the locking panel 17 to pass inwardly of the sleeve over therestraining panel 16 without substantial hindrance from the restrainingpanel 16, the locking panel 17 includes a first angle cut edge 17A. Thefirst angle cut edge 17A is adapted to just pass over the surface of therestraining panel 16 as the locking panel 17 is moved inwardly of thesleeve 10. As shown in FIG. 5, the restraining panel 16, when biasedagainst the tray end panel 31, forms an angle A relative to the bottompanel 11, and the first angle cut edge 17A is adapted to form an anglewith respect to the bottom panel 11 slightly greater than angle A. As aresult, the first angle cut edge 17A slides smoothly over the underlyingrestraining panel 16.

A second angle cut edge 17B is also included on the locking panel 17.The second angle cut edge 17B is adapted to provide the proper amount ofsurplusage of paperboard at this lateral, free edge 17B of locking panel17, the lateral surplusage portions associated with the second angle cutedge 17B hindering rotational movement of the locking panel 17, past thetray comer 32, into and out of the locking position thereof. By lockingposition is meant the location of the locking panels 17 between the trayside panel 33 and the sleeve side panels 12 and 14, as shown in FIGS. 4and 6. The lateral surplusage portions of the locking panel 17 are bentoutwardly of the sleeve as the locking panel 17 is urged past the traycorner 32 into the locking position inwardly of the sleeve 10. Theselateral portions of the locking panel 17 tend to be biased against thetray side panels 33 in the locking position due to the resiliency of thepaperboard hinge urging the locking panel 17 outwardly of the sleeve 10.In spite of the resiliency of the hinge of locking panel 17, however,the panel cannot swing back outwardly of the sleeve once it has beenforced into its locking position because it is restrained by the traycomer 32.

A third angle cut edge 17C is further included in locking panel 17. Inthis original sleeve 10, however, the third edge 17C is merely adaptedto avoid having the locking panel 17 strike the tray flange 34 when thelocking panel 17 is rotated inwardly of the sleeve 10.

FIGS. 5 and 6 show the underlying relationship of the restraining panel16 relative to the locking panel 17. The restraining panel 16 is biasedagainst the tray end panel 31 while the two fingers 26 of therestraining panel 16 cradle the tray end panel 31, the tray comers 32and the tray side panels 33 between them. The effect of the former andthe latter is to restrain both lengthwise and side to side movementrespectively of the tray in the sleeve 10. Each locking panel 17, in thelocking position, overlies the restraining panel 16 and/or a finger 26thereon. By overlying these restraining members, the locking panel 17resists the resilient tendency of the cardboard hinge 27 associated withthese members to move the restraining panel 16 outwardly of the sleeve10. It should be appreciated, however, that only one locking panel 17 ofthe configuration shown and discussed is necessary to adequately holdthe restraining panel 16 inwardly of the sleeve 10, two locking panelsbeing used only for purposes of a better appearing end construction andfor added restraint upon the tray 30 when the locking panels areactually biased thereagainst.

FIG. 7 shows half of a first modified blank, generally 100, for forminga first modified sleeve, also generally 100. The first modified blank100 differs from the original blank 10 in the numbering thereof by theaddition of 100 to the reference numerals of all corresponding members.Thus, first modified blank 100 has a glue flap 115, bottom panel 111,side panels 112 and 114, etc. However, epistemologically, the functionof the named members of the original sleeve 10 is intended to be carriedforward to the discussion of the same named members in the subsequentmodified sleeves 100, 200, 300 and 400, only the reference numeralsthereof being changed. The first .nodified blank 100 is substantiallysimilar to blank 10, the differences therebetween relating to theaddition of a second restraining panel 119, hingedly connected to thetop panel 113, and the changed configuration of the third angle cut 117Con locking panel 1 17.

As with the original blank 10 in FIG. 2, the first modified blank 100 asshown in FIG. 7 is formed into the first modified sleeve 100, as shownin FIG. 8. In the formed first modified sleeve 100, the locking panels117 and the restraining panels 116 and 119 extend outwardly of thesleeve 100, the tapered tray 30 being already positioned therein.

In forming the first modified end construction of the first modifiedsleeve, the restraining panels 116 and 119 are rotated inwardly of thesleeve 100 about their hinge lines, 127 and 128, respectively. In thisway the first restraining panel 116 is biased against the tray end panel32, and the fingers 126 on the first restraining panel 116 cradle thetray end panel 31. Additionally, the second restraining panel 119 isbiased against the tray end panel 31 and overlies the end portions ofthe tray flange 34. Provision for spaced fingers on the secondrestraining panel 119 is believed to be optional, such fingers havingbeen omitted in the second restraining panel 119 of the preferredembodiment of the first modified sleeve 100.

Then, as shown in FIG. 9, the locking panels 117 are rotated inwardly ofthe sleeve and are urged past the tray corners 32. The angle cut edges117A and 117C are adapted so that the locking panels 117 will slidesmoothly over both restraining panels 116 and 119 and will overlie thefingers 126 and underlie the lateral portions of the second restrainingpanel 119, the first edge 117A overlying the first restraining panel 116and the fingers 126, thereon, and the third edge 117C underly ing thesecond restraining panel 119. The second angle cut edge 1178 is adaptedso that the surplusage of the locking flap 117 can be pushed with somedifficulty past the tray comers 32 but at the same time the surplusageis sufficient to prevent the locking flap 117 from springing back, pastthe tray corner 32 and outwardly of the sleeve due to the resiliency ofthe cardboard material.

The third angle cut edge 117C is adapted to form an angle with respectto the top panel 113 of the sleeve 100 which is slightly greater than anangle C, shown in FIG. 10, angle cC being the angle between the secondrestraining panel 119 and the top panel 113. Similarly, the first anglecut edge 117A is adapted to be slightly greater than angle A as shown inFIG. 10 and as noted in the discussion concerning the first angle cutedge 17A in the sleeve 10. As a result, the first and third angle cutedges 117A and 117C provide the aforementioned smooth sliding duringrotation of the locking panels 117 inwardly of the first modified sleeve100.

FIG. 11 shows half of a second modified blank 200 for forming a secondmodified sleeve 200. The second modified blank 200 differs from theoriginal blank 10 in the numbering thereof by the addition of 200 to thereference numerals of all corresponding members. This, the secondmodified blank 200 has a glue fiap 215, bottom panel 211, side panels212 and 214, etc. The second modified blank 200 is substantially similarto the original blank 10, the difference therebetween relating to theaddition of the following: a third restraining panel 216A, having a pairof second, spaced fingers 226A that are hingedly attached to the firstspaced fingers 226 of the first restraining panel 216; a notch 216D inthe first restraining panel 216 in combination with a fourth angle cutedge 217D in the locking panel 217; and a plurality of tabs 218extending longitudinally from the end of the third restraining panel216A in combination with a plurality of knife cuts 220 located on thefirst hinge line 227, between the bottom panel 211 and the firstrestraining panel 216, the knife cuts 220 being adapted to having thetabs 218 inserted therein.

In forming the second modified sleeve 200, the second modified blank 200is formed into the sleeve 200 in the same manner as heretofore explainedwith regard to the original sleeve 10, the tray 30 then being insertedtherein. As shown in FIG. 12, the first and third restraining panels 216and 216A and the locking panels 217 extend outwardly of the sleeve 200.

As shown in FIG. 13, the third restraining panel 216A is then foldedover the first restraining panel 216 so that the second spaced fingers226A overlie the first spaced fingers 226 and the third restrainingpanel 216A overlies the first restraining panel 216. A scored, orotherwise preweakened, forth hinge line 225 is provided between thespaced fingers 226 and 226A to promote the folding operation. The overlying restraining panels provide a single reinforced cradle, having thegeneral configuration of the original restraining panel 16 with itsspaced fingers 26 extending outwardly of the sleeve 10, in the formedsecond modified sleeve 200.

As shown in FIG. 14, the overlying restraining panels 216 and 216A arethen rotated about the first hinge line 227 and are biased against thetray end panel 31, the spaced fingers 226 and 226A surrounding the traycorners 32 and the tray side panels 33. The tabs 218 extending from thethird restraining panel 216A are adapted to be inserted in the knifecuts 220 provided in the first hinge line 227 when the restrainingpanels are properly folded and biased against the tray end panel 31. Thecombination of tabs 218 and die cuts 220 provide this end constructionwith added strength and also prevent the folded restraining panels fromseparating during the interval of time between their being biasedagainst the tray end panel 31 and their being secured inwardly of thesleeve 200 by the locking panels 217. Of course, the number of tabs andknife cuts may be varied, either one or two being the preferred numberfor simplified insertion and registration thereof during the foldingoperation. Also, the tabs and knife cuts may be dispensed withaltogether in the second modified sleeve when the separation of the endportions of the third restraining panel 216A from the bottom portions ofthe first restraining panel 216, adjacent hinge line 227, is not aproblem.

As shown in FIG. 15, after biasing the restraining panels 216 and 216Aagainst the tray end panel 31, the locking panels 217 are foldedinwardly of the sleeve 200 and urged past the tray corners 32.

Angle cut edges 217A, 2173 and 217C have been provided, as heretoforenoted with regard to sleeves 10 and 100, the angle cut edges differingin several respects, however. In the second modified sleeve 200, thesecond angle cut edge 2178 is adapted to approximately conform to thetaper of the tray 30 at the corner 32 thereof, the surplusage of lockingpanel 217 being distributed along the length of the second angle cutedge 2178 rather than near the intersection of the first and secondangle cut edges A and B. The third angle cut edge 217C is adapted toavoid its striking the tray flange 34 when the locking panel 217 isrotated inwardly of the sleeve. it also provides the just notedsurplusage along the second angle cut edge 2178, rather than beingadapted to overlie a second restraining panel as noted in connectionwith the first modified sleeve 100.

The fourth angle cut edge 217D has been provided in locking panel 217and, in conjunction with the first angle cut edge 217A, is adapted tofit in locking relationship with the notch 216D provided in the firstrestraining panel 216. As shown in FIG. 16, when the locking panel 217is in locking position, having been forced inwardly of the secondmodified sleeve 200 past the tray corner 32, the first angle cut edge217A overlies the third restraining panel 216A, rather than the firstrestraining panel 216, and the fourth angle cut edge 217D overlies thefirst spaced finger 226. In this way, the locking panel 217 is fittedinto the notch 216D in the first restraining panel 216, and the lockingpanel 217 is prevented from moving outwardly of the sleeve by thesurplusage of paperboard associated with the first angle cut edge 217A.In this manner, the surplusage associated with the second angle cut edge217B may be entirely dispensed with, its function being provided by thesurplusage associated with the notch 216D and the fourth angle cut edge217D. Of course, to provide this new type of surplusage, the first anglecut edge 217 cannot be greater than angle A, as used with regard to theoriginal sleeve 10 and the first modified sleeve 100. Instead, the firstangle cut edge 217A must form an angle with the bottom panel 211 lessthan the angle A between the first restraining panel 216 and the bottompanel 211.

FIG. 17 shows a third modified paperboard sleeve 300, made from a blank,not shown, which is essentially the same as the second modified sleeve200 as shown in H6. 12, the reference numbering of the second modifiedsleeve being 200 and the third modified sleeve being 300. The thirdmodified sleeve 300 differs from the second modified sleeve 200 in thata second notch 316A!) has been provided in the third restraining panel316A. In much the same manner as the second modified sleeve 200, thethird modified sleeve is formed as follows: the third restraining panel316A is folded along the fourth hinge line 325 into overlyingrelationship with the first restraining panel 316. The restrainingpanels 316 and 316A are then biased against the tray end panel 31 byfolding them inwardly along the first hinge line 327. Tabs 318 and diecuts 320 have been provided in the third restraining panel 326A and thefirst hinge line 327, respectively, and the tabs 318 are inserted intothe die cuts 320 when the restraining panels are positioned inwardly ofthe third modified sleeve. The locking panels 317 are then pushedinwardly of the sleeve into locking position, the surplusage of lockingpanel 317 associated with the first and fourth edge cuts 317A and Drestraining the locking panel from outward movement relative to thethird modified sleeve 300. As shown in FIG. 18, the notches 316D and316AD are in vertical alignment providing thereby a greater notchedinterfit with the locking panel 317. Accordingly, it is anticipated thatthe first angle cut edge 317A and the fourth cut edge 317D will beadapted to provide a greater surplusage of paperboard in locking panel317 than was heretofore noted in the locking panel 217 of the secondmodified sleeve 200.

FIG. 19 shows a fourth modified blank 400 for fonning a fourth modifiedsleeve 400, shown in FIG. 20. The fourth modified blank and sleeve 400resemble the original blank and sleeve 10 with the followingmodifications: a notch 416D has been provided in the restraining panel416, a fourth cut edge 417D has been provided in the locking panel 417and a fifth cut edge 41715 has been provided in the locking panel 417.

The purpose in providing the notch 416D and the fourth cut edge 417D isto restrain the locking panel 417 in the locking position as heretoforenoted with regard to the second and third modified sleeves 200 and 300.Accordingly, the first angle cut edge 417A and the fourth angle cut edge417D are adapted to provide a surplusage of paperboard for interfittingrelationship with the notch 416D, the angle of the first angle cut edge417A with respect to the bottom panel 411 being less than the anglebetween the restraining panel 416 and the bottom panel 411.

The purpose of the fifth cut edge 417E, which represents a reliefbetween the sleeve top panel 413 and the locking panel 417, is to allowthe locking panel 417 to fit beneath the tray flange 34.

FIGS. 21 and 22 show the locking flap 417 positioned in the lockingposition, biased against the tray side panel 33, underneath the trayflange 34. The first angle cut edge 417A is beneath the restrainingpanel 416 and the fourth cut edge 417D of the locking panel 417 isoverlying the spaced fingers 426.

In view of the discussion with regard to the heretofore mentionedsleeves 10, 100, 200 and 3011, the end construction of the fourthmodified sleeve, involving the restraining panel 416, the locking panel417, the fingers 426 and the tapered tray 30 need not be set forth.However, the fourth modified sleeve 400 has one unique feature withrespect to the heretofore noted sleeves. The fourth modified sleeve 400is capable of having both its ends set up in locked relationship withthe end construction of the instant invention being formed at either oneor both ends thereof, and having a tapered tray subsequently insertedtherein. The tapered tray can be pushed through the substantially openend construction and cradled between the spaced fingers 426 of therestraining panel 416. During insertion of the tray 30, the restrainingpanel 416 is forced downward against the bottom panel 411 and thelocking panels 417 are forced laterally against the side panels 412 and414. Subsequent to insertion of the tray, due to the resiliency of thepaperboard sleeve, the members of the end construction return to thelocked position, the restraining panel 416 being loosely biased againstthe tray end panel 31 and the locking panels 417 being biased againstthe tray side panels 33 and overlying the spaced fingers 426.

It should be obvious from the discussion of the various embodiments ofthe end construction of the instant invention that many combinations andarrangements of the features disclosed herein can be made withoutdeparting from the scope of the invention. For instance, the secondrestraining panel 119 of the first modified sleeve could also be used inthe subsequent, modified sleeves 200, 300 and 400. Similarly, the

third restraining panels 216A and 316A as used in the second and thirdmodified sleeves 200 and 300 could also be used in the other sleevesdiscussed. Also similarly, the fifth cut edge 4175 as used in the fourthmodified sleeve 400 as well as the fourth angle cut edge 217D and 417Dand the first notch 216D and 416D as used in second and fourth modifiedsleeves could be incorporated into the other sleeves.

It should also be noted that it is anticipated that the paperboardsleeve of the instant invention will incorporate an easyopening featuresuch as the combination zipper pattern and removable side panel areaprovided in all the sleeves shown in FlGS. 1-22.

It should be further noted that each of the spaced fingers andrestraining panel combinations was provided with a rounded, cradlelikeedge contour for holding the tray corner. This contour has been dictatedby the fact that the frozen heat-and-serve tray used in the preferredembodiment has rounded comers, but the fingers may be aligned indifferent manners to accommodate different shaped trays and to cradle orsurround other articles in a substantially open-ended sleeve againstlateral movement of the ends portions of such articles.

It should be still further noted that all the end constructions of theinstant invention can be used at one or both ends of the sleeve. Sinceit may be desired to form one end of a sleeve before the tray isinserted therein, the arrangement of the notch on the restraining paneland the fourth cut edge on the locking panel may be required to preventthe locking and restraining panels from rotating outwardly of the sleeveas the tray is inserted therein. Of course, physically or otherwiseholding the locking panels inwardly of the sleeve until the tray iscradled in the restraining panel would be a satisfactory alternative.

It is further obvious that, in each of the sleeves hereinbeforedescribed, except for the fourth modified sleeve, the restraining panelcould depend from the top sleeve panel rather than from the bottomsleeve panel as herein shown. In each case, the angles of the cut edgesof the locking panels and the shape of the fingers of the restrainingpanel would be altered slightly because these elements would engage thetray walls closer to the upper, flanged end which is normally somewhatlarger than the lower wall portions due to the upwardly and outwardlytapering shape of the tray.

Finally, it is obvious that a single locking panel of the typesdescribed will serve to substantially prevent any of the correspondingrestraining panels from moving outwardly of the sleeve. However, it isalso believed that two locking panels provide a more attractive andsecure end construction than does one. In addition, two locking panels,except in the fourth modified sleeve 460 having the fifth cut edge 417E,provide some additional structural support to the sleeve panels againstthe crushing of the ends of the sleeve. This is an additional advantageof two locking panels over one locking panel.

It is thought that the invention and many of its attendant advantageswill be understood from the foregoing description and it will beapparent that various changes may be made in the form, construction andarrangement of the parts without departing from the spirit and scope ofthe invention or sacrificing all of its material advantages, the formhereinbefore described being merely a preferred embodiment thereof.

We claim:

1. A substantially open-ended paperboard sleeve, enclosing a taperedtray, the sleeve having a top, bottom and two side panels and having anend construction comprising:

a restraining panel, hingedly attached to the bottom panel and extendinginwardly of said sleeve into biased relationship against an end panel ofsaid tray, said restraining panel having two spaced fingers attached atthe lateral ends thereof for restricting the lateral movement of the endpanel of the tray with respect to said restraining panel, saidrestricting panel being further provided with a notch formed in a sideedge thereof; and

a locking panel hingedly attached to a sleeve side panel and extendinginwardly of said sleeve, a portion of the bottom ed e of saidlockingpanel overlying a portion of one of set restraining panel fingers and aportion of said locking panel bottom edge being lockingly engaged bysaid restraining panel notch, thereby to prevent movement of saidrestraining panel outwardly of said sleeve.

2. A paperboard blank for a substantially open-ended sleeve, comprising:

a plurality of hingedly connected sleeve-forming panels, including afirst panel and an adjacent second panel hingedly connected thereto;

a restraining panel hingedly connected to said first panel and a lockingpanel hingedly connected to said second panel and located substantiallyadjacent to said restraining panel;

said restraining panel being provided with a pair of spaced fingersattached at the lateral ends thereof and extending longitudinally fromthe edge of said restraining panel remote from said hinge connection tosaid first panel;

the free edge of said locking panel adjacent to said restraining panelforming an acute angle with the hinged edge between said locking paneland said second panel, said free edge being provided with a die cutlocking notch;

the free edge of said restraining panel adjacent to said locking panelhaving a locking notch formed therein;

said locking notches on said locking panel and said restraining panelbeing adapted to come into interlocking relationship when said blank isformed into a substantially open-ended sleeve and said restraining andlocking panels are infolded into cooperating relationship within saidsleeve.

3. A paperboard blank for a substantially open-ended sleeve, comprising:

a plurality of hingedly connected panels, including a first panel and anadjacent second panel hingedly connected thereto;

a restraining panel hingedly connected to said first panel and a lockingpanel hingedly connected to said second panel and located substantiallyadjacent to said restraining panel;

said restraining panel having an elliptical cutout about the centerthereof and having a transverse line of weakness through the centerthereof;

the lateral edge of said locking panel adjacent to said restrainingpanel forming an acute angle with respect to the hinged edge betweensaid second panel and said locking panel;

said restraining panel being further provided with a longitudinallyextending tab on the free edge thereof remote from the hinge connectionbetween the restraining panel and said first panel; and a transverseslit between said restraining panel and said first panel.

4. A blank as recited in claim 3, wherein the lateral edge of saidrestraining panel adjacent to said locking panel is provided with alocking notch, and the lateral edge of said locking panel adjacent tosaid restraining panel is provided with a die cut, said notch and saiddie cut being adapted to come into interlocking engagement when saidblank is formed into a substantially open-ended sleeve and saidrestraining and locking panels are infolded into cooperatingrelationship within said sleeve.

5. A blank as recited in claim 4 wherein said restraining panel isprovided with a plurality of notches.

1. A substantially open-ended paperboard sleeve, enclosing a taperedtray, the sleeve having a top, bottom and two side panels and having anend construction comprising: a restraining panel, hingedly attached tothe bottom panel and extending inwardly of said sleeve into biasedrelationship against an end panel of said tray, said restraining panelhaving two spaced fingers attached at the lateral ends thereof forrestricting the lateral movement of the end panel of the tray withrespect to said restraining panel, said restricting panel being furtherprovided with a notch formed in a side edge thereof; and a locking panelhingedly attached to a sleeve side panel and extending inwardly of saidsleeve, a portion of the bottom edge of said locking panel overlying aportion of one of said restraining panel fingers and a portion of saidlocking panel bottom edge being lockingly engaged by said restrainingpanel notch, thereby to prevent movement of said restraining paneloutwardly of said sleeve.
 2. A paperboard blank for a substantiallyopen-ended sleeve, comprising: a plurality of hingedly connectedsleeve-forming panels, including a first panel and an adjacent secondpanel hingedly connected thereto; a restraining panel hingedly connectedto said first panel and a locking panel hingedly connected to saidsecond panel and located substantially adjacent to said restrainingpanel; said restraining panel being provided with a pair of spacedfingers attached at the lateral ends thereof and extendinglongitudinally from the edge of said restraining panel remote from saidhinge connectioN to said first panel; the free edge of said lockingpanel adjacent to said restraining panel forming an acute angle with thehinged edge between said locking panel and said second panel, said freeedge being provided with a die cut locking notch; the free edge of saidrestraining panel adjacent to said locking panel having a locking notchformed therein; said locking notches on said locking panel and saidrestraining panel being adapted to come into interlocking relationshipwhen said blank is formed into a substantially open-ended sleeve andsaid restraining and locking panels are infolded into cooperatingrelationship within said sleeve.
 3. A paperboard blank for asubstantially open-ended sleeve, comprising: a plurality of hingedlyconnected panels, including a first panel and an adjacent second panelhingedly connected thereto; a restraining panel hingedly connected tosaid first panel and a locking panel hingedly connected to said secondpanel and located substantially adjacent to said restraining panel; saidrestraining panel having an elliptical cutout about the center thereofand having a transverse line of weakness through the center thereof; thelateral edge of said locking panel adjacent to said restraining panelforming an acute angle with respect to the hinged edge between saidsecond panel and said locking panel; said restraining panel beingfurther provided with a longitudinally extending tab on the free edgethereof remote from the hinge connection between the restraining paneland said first panel; and a transverse slit between said restrainingpanel and said first panel.
 4. A blank as recited in claim 3, whereinthe lateral edge of said restraining panel adjacent to said lockingpanel is provided with a locking notch, and the lateral edge of saidlocking panel adjacent to said restraining panel is provided with a diecut, said notch and said die cut being adapted to come into interlockingengagement when said blank is formed into a substantially open-endedsleeve and said restraining and locking panels are infolded intocooperating relationship within said sleeve.
 5. A blank as recited inclaim 4 wherein said restraining panel is provided with a plurality ofnotches.